• Journal of the Korean Ceramic Society
• /
• v.23 no.3
• /
• pp.94-98
• /
• 1986

Infrared has been used in determination of water in magnesium metaphosphate glasses. The method consisted of measuring the weight loss and the variation in absorption coefficient at 3, 200$cm^{-1}$. The molar absorptivity of water in magnesium metaphophate glasses was found to 76.9ι$mol^{-1} cm^{-1}$ Using the value for $\varepsilon$, A and Δ$\upsilon$H of the hydroxyl band in the spectra of magnesium metaphosphate. The molar absorptivity of the hydroxyl absorption band at 3, 3130-2, $925cm^{-1}$ in the spectra of MgO.$P_2O_5$ system glasses could be computed. And a variation of molar absorptivity against the MgO/P2O5 ratio has not been shown regulation.

• Transactions of the Korean Society of Mechanical Engineers
• /
• v.11 no.3
• /
• pp.409-424
• /
• 1987

Simulation on the hot water ONDOL heating system was made in order to investigate the variation of room temperature and specific fuel consumption of boiler. Heat balance equation was derived by response factors and solved implicitly. Variation of room temperature and specific fuel consumption of boiler were calculated with respect to the thickness of room floor, the absorptivity of wall for solar radiation, on-off temperature range of boiler and air exchange. The results show that specific fuel consumption of boiler is independent of the thickness of room floor and decreases with increasing the absorptivity of wall and on-off temperature range of boiler. However, it increases with increasing the air exchange. They also show that, when the absorptivity and on-off temperature range of boiler are increased, the amplitudes of room temperature variation increase.

• Journal of the Korea Furniture Society
• /
• v.19 no.3
• /
• pp.172-179
• /
• 2008

The objective of this study was to investigate the influence of the water repellents' treatment on the water absorptivity and the dimensional stability of Korean red pine wood(Pinus densiflora). The alkylketene dimer(AKD), fluororesin emulsion(Wood-seal, WS), and paraffin wax emulsions(PW25, PW40, and PW1200) were used as water repellents. PW40 and WS were proved as excellent water repellents for pine wood, because the samples treated with these agents showed high contact angles and large reduction in water absorptivities. Also, the dimensional stability(antiswelling efficiency) of pine wood was considerably improved by water repellents treatments, such as PW40 and WS at the pressure of 2MPa. The water repellent treated woods with WS, PW40, and PW1200 at the pressure of 2MPa were relatively stable to the wet-dry cyclic leaching test.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.585-588
• /
• 2006

The environment-friendly building material, photocatalyst/scoria/loess concrete, was prepared using scoria and loess (which have merits as building materials) and photocatalyst (which has the functions to compose the environmental contaminants and of self cleaning). In order to apply this material as a building material, the compressive and flexible strengths, and water absorptivity (which have been set by Korea Industrial Standard) were measured. The optimum mixing ratio of photocatalyst/scoria/loess concrete was obtained at the condition of $393kg/m^3$ of coarse aggregate, $802kg/m^3$ of fine aggregate in case of scoria, $80kg/m^3$ of loess, $12kg/m^3$ of photocatalyst, $400kg/m^3$ of cement, and $2kg/m^3$ of AE water reducing agent. The photocatalyst/scoria/loess concrete prepared by above mixing ratio of raw materials showed 25 MPa of compressive strength, $3.8{\sim}4.6$ MPa of flexible strength and $11.4{\sim}12.0%$ of water absorptivity, indicating that the quality of this material was suitable for Korea Industrial Standard (more than 21 MPa for compressive strength, more than 2.0 MPa for flexible strength in case of lightweight aggregate, and less than 15 % for water absorptivity in case of clay brick) for using as a building material.

• Journal of the Korean Wood Science and Technology
• /
• v.43 no.3
• /
• pp.334-343
• /
• 2015

This study was carried out to evaluate quantitatively some properties (density, equilibrium moisture content, shrinkage, water vapor adsorption, water absorptivity, compressive strength, bending strength, hardness and decay resistance) of Larix kaempferi lumber which was heat-treated by hot air and has been used commercially in Korea. Equilibrium moisture content of the heat-treated wood was decreased with increase of hydrophobicity. Dimensional stability of the wood was improved with decrease of shrinkage, water vapor adsorption and free water absorptivity. Also, with the thermo-chemical changes of wood component and lower equilibrium moisture content, decay resistance and compressive strength of heat-treated wood were increased. But, bending strength and hardness of wood were decreased.

• Journal of the Korean Society of Safety
• /
• v.13 no.2
• /
• pp.39-44
• /
• 1998

An experimental study on oil absorbent was conducted to investigate the feasibility of utilizing absorbents in oil separation from water-oil mixture for spilt oil recovery. Experiments included investigations of absorptivity and filtering performance of a commercial oil absorbent for different diesel oil concentrations. The measured average absorptivity of the absorbent was above 92% for oil concentrations, 5, 10, 15vo1%, that shows good absorbing performance. Filtering the oil-water mixture, however, was too slow to be used for oil separation. An absorbent baffle system was suggested for oil separation which collects oil panicles by increasing contact between the absorbent and oil particles.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.593-596
• /
• 2006

The environment-friendly building material, photocatalyst/scoria/loess concrete, was prepared using scoria and loess (which have merits as building materials) and photocatalyst (which has the functions to compose the environmental contaminants and of self cleaning). In order to apply this material as a building material, the compressive and flexible strengths, and water absorptivity (which have been set by Korea Industrial Standard) were measured. In order to know the environment-friendly characteristics of this material, several tests, such as, the tests of emissivity and emission power of far infrared ray and acoustic absorptivity, antibacterial test for Escherichia coli and Pseudomonas aeruginosa, antifungal test for mixed fungal strains, and deodorization test of ammonia were carried out. Moreover, the removal characteristics of NOx, and formaldehyde (HCHO) by photocatalyst/scoria/loess concrete were examined as the following different parameters: the removal characteristics of these contaminants with the substitution ratio and the kind of photocatalyst, light source, UV intensity of sunlight, relative humidity, intial NOx concentration.

• Korean Journal of Remote Sensing
• /
• v.11 no.1
• /
• pp.31-45
• /
• 1995

The values of brightness temperature difference (BTD) between 11um and 12um infrared channels may reflect amounts of low-level water vapor and cloud types due to the different absorptivity for water vapor between two channels. A simple method of classifying cloud types at night was proposed. Two-dimensional histograms of brightness temperature of the 11um channel and the BTD between the split window data over subareas around characteristic clouds such as Cb(cumulonimbus), Ci(cirrus), and Sc(stratocumulus) was constructed. Cb, Ci and Sc can be classified by seleting appropriate thresholds in the two-dimensional histograms. And we can see amounts of low-level water vapor in clear area as well as cloud types in cloudy area in the BTD image. The map of cloud types and low-level water vapor generated by this method was compared with 850hPa and 1000hPa relative humidity(%) of numerical analysis data and nephanalysis chart. The comparisons showed reasonable agreement.

• Rapid Communication in Photoscience
• /
• v.4 no.3
• /
• pp.67-69
• /
• 2015

FTIR spectroscopy has been employed to investigate the variation of anion-water hydrogen bonding in 1-butyl 3-methyl imidazolium tetrafluoroborate ([Bmim][$BF_4$]) ionic liquid caused by addition of organic co-solvents with various polarities. The variation was estimated by probing band shape and intensity of the OH stretching vibration of trace water present in ionic liquid at $3400-3800cm^{-1}$. The presence of polar aprotic co-solvent in ionic liquid dramatically reduces the absorptivity of the OH stretch band, indicating that the co-solvent changes the nature of anion-water hydrogen bond drastically, which might be responsible for the reduction of the viscosity of ionic liquid in the presence of the co-solvent.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
• /
• v.25 no.3
• /
• pp.119-125
• /
• 2013

IInsulation material is generally used for preventing heat loss from heat transport fluids, and water absorption severely reduces the insulation property. The purpose of this study is to evaluate the amount of water absorption supplied by the pouring method and spraying method, to investigate the effects of water absorption on the thermal conductivity of an insulation material, and modeling the relation between water absorption and thermal conductivity. E-glass, a kind of glass fiber, and HYPERLITE, mainly composed of pearlite, are selected, to compare hygroscopic and insulation properties. E-glass is found to have much higher water absorptivity, compared to HYPERLITE. The thermal conductivity of the water-absorbed E-glass is increased by more than 150%, compared to that of no absorption, while variation of the thermal conductivity of HYPERLITE with water absorption is insignificant. A three-stage model of water absorption for thermal conductivity is developed, and the modeling results are found to be in good agreement with the experimental data.